Nowadays most portable electronic devices have some sort of network capability. However, due to different power, cost and processing limitations, the choice of networking technology changes for each device. Currently, networks are converging to all-IP solutions, due to their wide applicability and low cost. However, the IP architecture is built on several design decisions that complicate the support of ubiquitous networking. In order to allow the equipment to intercommunicate even though their protocols may be different, a new set of protocols and services have been developed. This article describes the challenges and existing solutions in the area of convergent networking protocols and architectures. First, we will explore why the TCP/IP architecture is not tailored to mobile networks, briefly describing its limitations and possible solutions. Next, we will present a taxonomy to classify the architectures for convergent networking. Finally, we show a brief survey of the existing convergent architectures as well as the research challenges on the subject.